Dr. Zensheu Chang Profile

Dr. Zensheu Chang

at Jet Propulsion Lab

SPIE Involvement:

Author

Publications (49)

Proceedings Article | 18 October 2017 Presentation

IMPipeline: an integrated STOP modeling pipeline for the WFIRST coronagraph (Conference Presentation)

Navtej Saini, Kevin Anderson, Zensheu Chang, Gary Gutt, Bijan Nemati

Proceedings Volume 10400, 1040008 (2017) https://doi.org/10.1117/12.2274260

KEYWORDS: Thermography, Software development, Infrared telescopes, Space telescopes, Stars, Planets, Optical analysis, Error analysis, Integrated modeling, Infrared radiation

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Proceedings Article | 16 September 2015 Paper

Requirements and design reference mission for the WFIRST/AFTA coronagraph instrument

Richard Demers, Frank Dekens, Rob Calvet, Zensheu Chang, Robert Effinger, Eric Ek, Larry Hovland, Laura Jones, Anthony Loc, Bijan Nemati, Charley Noecker, Timothy Neville, Hung Pham, Mike Rud, Hong Tang, Juan Villalvazo

Proceedings Volume 9605, 960502 (2015) https://doi.org/10.1117/12.2191792

KEYWORDS: Coronagraphy, Collimators, Space telescopes, Telescopes, Iterated function systems, Planets, Mirrors, Exoplanets, Electronics, Thermography

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Proceedings Article | 26 September 2013 Paper

Wide-Field InfraRed Survey Telescope (WFIRST) 2.4-meter mission study

D. Content, K. Aaron, L. Abplanalp, K. Anderson, R. Capps, Z. Chang, J. Dooley, R. Egerman, R. Goullioud, D. Klein, J. Kruk, G. Kuan, M. Melton, J. Ruffa, M. Underhill, D. Van Buren

Proceedings Volume 8860, 88600E (2013) https://doi.org/10.1117/12.2027717

KEYWORDS: Space telescopes, Telescopes, Space operations, Coronagraphy, Imaging spectroscopy, Exoplanets, Observatories, Infrared telescopes, Mirrors, Electronics

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Proceedings Article | 19 April 2013 Paper

Percussive augmenter of rotary drills (PARoD)

Mircea Badescu, Jennifer Hasenoehrl, Yoseph Bar-Cohen, Stewart Sherrit, Xiaoqi Bao, Zensheu Chang, Patrick Ostlund, Jack Aldrich

Proceedings Volume 8692, 86921Q (2013) https://doi.org/10.1117/12.2010316

KEYWORDS: Actuators, Ferroelectric materials, Ultrasonics, Teeth, Transducers, 3D modeling, Statistical analysis, Planets, Prototyping, Baryon acoustic oscillations

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Proceedings Article | 21 September 2012 Paper

Wide Field Infrared Survey Telescope [WFIRST]: telescope design and simulated performance

R. Goullioud, D. Content, G. Kuan, J. Moore, Z. Chang, E. Sunada, J. Villalvazo, J. Hawk, N. Armani, E. Johnson, C. Powell

Proceedings Volume 8442, 84421U (2012) https://doi.org/10.1117/12.927808

KEYWORDS: Mirrors, Telescopes, Space telescopes, Computer aided design, Thermography, Infrared telescopes, Optical instrument design, Performance modeling, Thermal modeling, Finite element methods

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Proceedings Article | 3 April 2012 Paper

Single piezo-actuator rotary-hammering (SPaRH) drill

Stewart Sherrit, Lukas Domm, Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang, Mircea Badescu

Proceedings Volume 8345, 83452B (2012) https://doi.org/10.1117/12.915379

KEYWORDS: Transducers, Actuators, Finite element methods, Prototyping, Computer aided design, Sensors, Data modeling, Photography, Ultrasonics, Circuit switching

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Proceedings Article | 3 April 2012 Paper

Miniaturization of planar horn motors

Stewart Sherrit, Patrick Ostlund, Zensheu Chang, Xiaoqi Bao, Yoseph Bar-Cohen, Scott Widholm, Mircea Badescu

Proceedings Volume 8345, 83452C (2012) https://doi.org/10.1117/12.915387

KEYWORDS: Actuators, Computer aided design, Solid modeling, Electromechanical design, Prototyping, Manufacturing, Ceramics, Electronic test equipment, Titanium, Finite element methods

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Proceedings Article | 16 April 2011 Paper

Sensor for direct measurement of the boundary shear stress in fluid flow

Xiaoqi Bao, Mircea Badescu, Yoseph Bar-Cohen, Shyh-Shiuh Lih, Stewart Sherrit, Zensheu Chang, Beck Chen, Scott Widholm, Patrick Ostlund

Proceedings Volume 7981, 79814G (2011) https://doi.org/10.1117/12.880901

KEYWORDS: Sensors, Computer programming, Bridges, Velocity measurements, Turbulence, Spatial resolution, Prototyping, Optical encoders, Calibration, Protactinium

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Proceedings Article | 13 April 2011 Paper

Planar rotary motor using ultrasonic horns

Stewart Sherrit, Xiaoqi Bao, Mircea Badescu, Zensheu Chang, Daniel Geiyer, Phillip Allen, Patrick Ostlund, Yoseph Bar-Cohen

Proceedings Volume 7981, 79810O (2011) https://doi.org/10.1117/12.880496

KEYWORDS: Actuators, Computer aided design, Ultrasonics, Prototyping, Manufacturing, Solid modeling, Motion models, Electron beam melting, Rapid manufacturing, Titanium

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Proceedings Article | 22 July 2010 Paper

Progress on SIM-Lite brassboard interferometer integration and test

I. Hahn, M. Weilert, X. An, G. Kuan, L. Hovland, R. Smythe, E. Hovland, R. Krylo, M. Fisher, Z. Chang, J. Cepeda-Rizo, J. Shields, A. Ahmed, N. Fathpour, J. Carson, F. Nicaise, M. Morales, F. Dekens, R. Goullioud

Proceedings Volume 7734, 77344K (2010) https://doi.org/10.1117/12.858288

KEYWORDS: Interferometers, Stars, Modulation, Mirrors, Telescopes, Metrology, Beam splitters, Cameras, CCD image sensors, Interferometry

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Proceedings Article | 1 April 2010 Paper

Direct measurement sensor of the boundary shear stress in fluid flow

Mircea Badescu, Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang, Kornel Kerenyi, Shyh-Shiuh Lih, Stewart Sherrit, Brian Trease, Beck Chen, Scott Widholm

Proceedings Volume 7647, 76471C (2010) https://doi.org/10.1117/12.847325

KEYWORDS: Sensors, Computer programming, Interferometers, Velocity measurements, Bridges, Head, Turbulence, Spatial resolution, Sensing systems, Laser Doppler velocimetry

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Proceedings Article | 28 July 2008 Paper

Extracting the zero-gravity surface figure of a mirror

E. Bloemhof, J. Lam, V. Feria, Z. Chang

Proceedings Volume 7013, 70133L (2008) https://doi.org/10.1117/12.790532

KEYWORDS: Mirrors, Finite element methods, Spherical lenses, Metrology, Prototyping, Surface finishing, Polishing, Mirror mounts, Interferometry, Optical testing

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Proceedings Article | 19 March 2008 Paper

High-power piezoelectric acoustic-electric power feedthru for metal walls

Xiaoqi Bao, Will Biederman, Stewart Sherrit, Mircea Badescu, Yoseph Bar-Cohen, Christopher Jones, Jack Aldrich, Zensheu Chang

Proceedings Volume 6930, 69300Z (2008) https://doi.org/10.1117/12.776473

KEYWORDS: Wave plates, Transducers, Metals, Titanium, Finite element methods, Amplifiers, Prototyping, Ceramics, Reflectors, Transmitters

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Proceedings Article | 19 April 2007 Paper

Wireless piezoelectric acoustic-electric power feedthru

Xiaoqi Bao, Benjamin Doty, Stewart Sherrit, Mircea Badescu, Yoseph Bar-Cohen, Jack Aldrich, Zensheu Chang

Proceedings Volume 6529, 652940 (2007) https://doi.org/10.1117/12.716429

KEYWORDS: Prototyping, Data communications, Acoustics, Aluminum, Amplifiers, Ceramics, Wave plates, Communication engineering, Space operations, Circuit switching

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Proceedings Article | 19 April 2007 Paper

Ultrasonic/sonic driller/corer as a hammer-rotary drill

M. Badescu, S. Kassab, S. Sherrit, J. Aldrich, X. Bao, Y. Bar-Cohen, Z. Chang

Proceedings Volume 6529, 65290S (2007) https://doi.org/10.1117/12.716493

KEYWORDS: Actuators, Transducers, Ultrasonics, Modal analysis, Baryon acoustic oscillations, Mars, Acoustics, Spectrometers, Neck, 3D modeling

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Proceedings Article | 19 April 2007 Paper

Power loss consideration in wireless piezoelectric acoustic-electric power feedthru

Zensheu Chang, Xiaoqi Bao, Benjamin Doty, Stewart Sherrit, Yoseph Bar-Cohen, Mircea Badescu, Jack Aldrich

Proceedings Volume 6529, 652942 (2007) https://doi.org/10.1117/12.716433

KEYWORDS: Transducers, Wave plates, Acoustics, Ferroelectric materials, Wave propagation, Finite element methods, Receivers, Chemical elements, Space operations, Circuit switching

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Proceedings Article | 18 April 2007 Paper

Lyapunov stability of periodically modulated cosine drivers for resonance tuning of harmonic oscillators

J. Aldrich, S. Sherrit, X. Bao, M. Badescu, Y. Bar-Cohen, Z. Chang

Proceedings Volume 6523, 65230B (2007) https://doi.org/10.1117/12.716403

KEYWORDS: Oscillators, Telecommunications, Linear filtering, Control systems, Complex systems, Inspection, Systems modeling, Sensors, Feedback control, Real-time computing

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Proceedings Article | 10 April 2007 Paper

Subsurface sampler and sensors platform using the ultrasonic/sonic driller/corer (USDC)

Yoseph Bar-Cohen, Stewart Sherrit, Xiaoqi Bao, Mircea Badescu, Jack Aldrich, Zensheu Chang

Proceedings Volume 6529, 65290E (2007) https://doi.org/10.1117/12.715048

KEYWORDS: Sensors, Actuators, Ultrasonics, Statistical analysis, Biological research, Baryon acoustic oscillations, Fiber optics, Temperature metrology, Teeth, Astrobiology

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The search for existing or past life in the Universe is one of the most important objectives of NASA's mission. For this purpose, effective instruments that can sample and conduct in-situ astrobiology analysis are being developed. In support of this objective, a series of novel mechanisms that are driven by an Ultrasonic/Sonic actuator have been developed to probe and sample rocks, ice and soil. This mechanism is driven by an ultrasonic piezoelectric actuator that impacts a bit at sonic frequencies through the use of an intermediate free-mass. Ultrasonic/Sonic Driller/Corer (USDC) devices were made that can produce both core and powdered cuttings, operate as a sounder to emit elastic waves and serve as a platform for sensors. For planetary exploration, this mechanism has the important advantage of requiring low axial force, virtually no torque, and can be duty cycled for operation at low average power. The advantage of requiring low axial load allows overcoming a major limitation of planetary sampling in low gravity environments or when operating from lightweight robots and rovers. The ability to operate at duty cycling with low average power produces a minimum sample temperature rise allowing for control of the sample integrity and preventing damage to potential biological markers in the acquired sample. The development of the USDC is being pursued on various fronts ranging from analytical modeling to mechanisms improvements while considering a wide range of potential applications. While developing the analytical capability to predict and optimize its performance, efforts are made to enhance its capability to drill at higher power and high speed. Taking advantage of the fact that the bit does not require rotation, sensors (e.g., thermocouple and fiberoptics) were integrated into the bit to examine the borehole during drilling. The sounding effect of the drill was used to emit elastic waves in order to evaluate the surface characteristics of rocks. Since the USDC is driven by piezoelectric actuation mechanism it can designed to operate at extreme temperature environments from very cold as on Titan and Europa to very hot as on Venus. In this paper, a review of the latest development and applications of the USDC will be given.

Proceedings Article | 30 March 2006 Paper

Studies of acoustic-electric feed-throughs for power transmission through structures

Stewart Sherrit, Benjamin Doty, Mircea Badescu, Xiaoqi Bao, Yoseph Bar-Cohen, Jack Aldrich, Zensheu Chang

Proceedings Volume 6171, 617102 (2006) https://doi.org/10.1117/12.657736

KEYWORDS: Epoxies, Transducers, Acoustics, Chemical elements, Prototyping, Mechanical efficiency, Solid modeling, Data communications, Dielectrics, Mars

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There are numerous engineering design problems where the use of wires to transfer power and communicate data thru the walls of a structure is prohibitive or significantly difficult that it may require a complex design. Using physical feedthroughs in such systems may make them susceptible to leakage of chemicals or gasses, loss of pressure or vacuum, as well as difficulties in providing adequate thermal or electrical insulation. Moreover, feeding wires thru a wall of a structure reduces the strength of the structure and makes the structure prone to cracking due to fatigue that can result from cyclic loading and stress concentrations. One area that has already been identified to require a wireless alternative to electrical feedthroughs would be the container of any Mars Sample Return Mission, which would need wireless sensors to sense a pressure leak and to avoid potential contamination. The idea of using elastic or acoustic waves to transfer power was suggested recently by [Y. Hu, et al., July 2003]. This system allows for the avoidance of cabling or wiring. The technology is applicable to the transfer of power for actuation, sensing and other tasks inside any sealed container or vacuum/pressure vessel. An alternative approach to the modeling presented previously [Sherrit et al., 2005] used network analysis to solve the same problem in a clear and expandable manner. Experimental tests on three different designs of these devices were performed. The three designs used different methods of coupling the piezoelectric element to the wall. In the first test the piezoelectric material was bolted using a backing structure. In the second test the piezoelectric was clamped after the application of grease. Finally the piezoelectric element was attached using a conductive epoxy. The mechanical clamp with grease produced the highest measured efficiency of 53% however this design was the least practical from a fabrication viewpoint. The power transfer efficiency of conductive epoxy joint was 40% and the stress bolts (12%). The experimental results on a variety of designs will be presented and the thermal and non-linear issues will be discussed.

Proceedings Article | 30 March 2006 Paper

USDC based rapid penetrator of packed soil

X. Bao, Y. Bar-Cohen, Z. Chang, S. Sherrit, M. Badescu, S. Du, T. Song, T. Peterson

Proceedings Volume 6171, 617108 (2006) https://doi.org/10.1117/12.658630

KEYWORDS: Transducers, Prototyping, Ultrasonics, Baryon acoustic oscillations, Head, Ferroelectric materials, Testing and analysis, Chemical analysis, Robotics, Soil contamination

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Proceedings Article | 30 March 2006 Paper

Ultrasonic/sonic gopher for subsurface ice and brine sampling: analysis and fabrication challenges and testing results

M. Badescu, S. Sherrit, A. Olorunsola, J. Aldrich, X. Bao, Y. Bar-Cohen, Z. Chang, P. Doran, C. Fritsen, F. Kenig, C. McKay, A. Murray, S. Du, T. Peterson, T. Song

Proceedings Volume 6171, 617107 (2006) https://doi.org/10.1117/12.657487

KEYWORDS: Transducers, Actuators, Neck, Ultrasonics, Mars, Head, Computer aided design, Planets, Astrobiology, Modal analysis

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Proceedings Article | 30 March 2006 Paper

Reaction force of percussive corer, rotary-friction corer, and rotary-percussive corer

Zensheu Chang, Stewart Sherrit, Mircea Badescu, Xiaoqi Bao, Yoseph Bar-Cohen, Paul Backes

Proceedings Volume 6171, 617106 (2006) https://doi.org/10.1117/12.658075

KEYWORDS: Ultrasonics, Robotics, Mars, Motion models, Software, Francium, Chromium, Transducers, Baryon acoustic oscillations, Teeth

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Proceedings Article | 27 March 2006 Paper

Extremum-seeking control for an ultrasonic/sonic driller/corer (USDC) driven at high power

Jack Aldrich, Stewart Sherrit, Xiaoqi Bao, Yoseph Bar-Cohen, Mircea Badescu, Zensheu Chang

Proceedings Volume 6166, 616618 (2006) https://doi.org/10.1117/12.658872

KEYWORDS: Actuators, Ultrasonics, Transducers, Detection and tracking algorithms, Resonators, Curium, Control systems, Signal to noise ratio, Baryon acoustic oscillations, LabVIEW

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Future NASA exploration missions will increasingly require sampling, in-situ analysis and possibly the return of material to Earth for further tests. One of the challenges to addressing this need is the ability to drill using minimal reaction force and torque while operating from light weight platforms (e.g., lander, rover, etc.) as well as operate at planets with low gravity. For this purpose, the authors developed the Ultrasonic/Sonic Driller/Corer (USDC) jointly with Cybersonics Inc. Studies of the operation of the USDC at high power have shown there is a critical need to self-tune to maintain the operation of the piezoelectric actuator at resonance. Performing such tuning is encountered with difficulties and to address them an extremum-seeking control algorithm is being investigated. This algorithm is designed to tune the driving frequency of a time-varying resonating actuator subjected to both random and high-power impulsive noise disturbances. Using this algorithm, the performance of the actuator is monitored on a time-scale that is compatible with its slowly time-varying physical characteristics. The algorithm includes a parameter estimator, which estimates the coefficients of a function that characterizes the quality factor of the USDC. Since the parameter estimator converges sufficiently faster than the time-varying drift of the USDC's actuator physical parameters, this extremum-seeking estimation and control algorithm potentially allows for use in closed-loop monitoring of the operation of the USDC. Specifically, this system may be programmed to automatically adjust the duty-cycle of the sinusoidal driver signal to monitor the quality factor of the USDC not to fall below a user-defined set-point. Such fault-tolerant functionality is especially important in automated drilling applications where it is essential not to inadvertently drive the piezoelectric ceramic elements of the USDC beyond their operation capability. The details of the algorithm and experimental results are described and discussed in this paper.

Proceedings Article | 17 May 2005 Paper

Integrated modeling of the utrasonic/sonic drill/corer (USDC): procedure and analysis results

Mircea Badescu, Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang, Stewart Sherrit

Proceedings Volume 5764, (2005) https://doi.org/10.1117/12.598886

KEYWORDS: Transducers, Neck, Ultrasonics, Modal analysis, Integrated modeling, C++, Chemical elements, Baryon acoustic oscillations, Data modeling, MATLAB

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Proceedings Article | 16 May 2005 Paper

Efficient electromechanical network model for wireless acoustic-electric feed-throughs

Stewart Sherrit, Mircea Badescu, Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang

Proceedings Volume 5758, (2005) https://doi.org/10.1117/12.598300

KEYWORDS: Acoustics, Transformers, Transducers, Ferroelectric materials, Head, Data modeling, Dielectrics, Chemical elements, Electromechanical design, Data communications

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There are numerous engineering design problems where the use of wires to transfer power and communicate data thru the walls of a structure is prohibitive or significantly difficult that it may require a complex design. Such systems may be concerned with the leakage of chemicals or gasses, loss of pressure or vacuum, as well as difficulties in providing adequate thermal or electrical insulation. Moreover, feeding wires thru a wall of a structure reduces the strength of the structure and makes the structure susceptibility to cracking due to fatigue that can result from cyclic loading. Two areas have already been identified to require a wireless alternative capability and they include (a) the container of the Mars Sample Return Mission will need the use of wireless sensors to sense pressure leak and to avoid potential contamination; and (b) the Navy is seeking the capability to communicate with the crew or the instrumentation inside marine structures without the use of wires that will weaken the structure. The idea of using elastic or acoustic waves to transfer power was suggested recently by Y. Hu, et al.1. However, the disclosed model was developed directly from the wave equation and the linear equations of piezoelectricity. This model restricted by an inability to incorporate head and tail mass and account for loss in all the mechanisms. In addition there is no mechanism for connecting the model to actual power processing circuitry (diode bridge, capacitors, rectifiers etc.). An alternative approach which is to be presented is a network equivalent circuit that can easily be modified to account for additional acoustic elements and connected directly to other networks or circuits. All the possible loss mechanisms of the disclosed solution can be accounted for and introduced into the model. The circuit model allows for both power and data transmission in the forward and reverse directions through acoustic signals at the harmonic and higher order resonances. This system allows or the avoidance of cabling or wiring. The technology is applicable to the transfer of power for actuation, sensing and other tasks inside sealed containers and vacuum/pressure vessels.

Proceedings Article | 6 May 2005 Paper

Wirelessly controllable inflated electroactive polymer (EAP) reflectors

Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang, Stewart Sherrit, Mircea Badescu

Proceedings Volume 5759, (2005) https://doi.org/10.1117/12.599787

KEYWORDS: Electroactive polymers, Reflectors, Algorithm development, Baryon acoustic oscillations, Mirrors, Polymers, Chemical elements, Spherical lenses, Control systems, Protactinium

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Proceedings Article | 5 May 2005 Paper

Adapting the ultrasonic/sonic driller/corer for walking/climbing robotic applications

Mircea Badescu, Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang, Borna Dabiri, Brett Kennedy, Stewart Sherrit

Proceedings Volume 5762, (2005) https://doi.org/10.1117/12.598870

KEYWORDS: Stars, Ultrasonics, Actuators, Robotics, Robotic systems, Transducers, Algorithm development, Bone, Baryon acoustic oscillations, Planets

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Proceedings Article | 5 May 2005 Paper

The ultrasonic/sonic driller/corer (USDC) as a subsurface drill, sampler, and lab-on-a-drill for planetary exploration applications

Y. Bar-Cohen, Z. Chang, S. Sherrit, M. Badescu, X. Bao

Proceedings Volume 5762, (2005) https://doi.org/10.1117/12.599703

KEYWORDS: Ultrasonics, Actuators, Sensors, Statistical analysis, Baryon acoustic oscillations, Bone, Astrobiology, Robots, Interfaces, Temperature metrology

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Proceedings Article | 5 May 2005 Paper

Design and analysis of ultrasonic actuator in consideration of length reduction for a USDC (ultrasonic/sonic driller/corer)

Zensheu Chang, Stewart Sherrit, Mircea Badescu, Xiaoqi Bao, Yoseph Bar-Cohen

Proceedings Volume 5762, (2005) https://doi.org/10.1117/12.598851

KEYWORDS: Ultrasonics, Actuators, 3D modeling, Modal analysis, Statistical analysis, Baryon acoustic oscillations, Finite element methods, Robotics, Interfaces, Smart materials

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Proceedings Article | 29 July 2004 Paper

Subsurface ice and brine sampling using an ultrasonic/sonic gopher for life detection and characterization in the McMurdo dry valleys

Yoseph Bar-Cohen, Stewart Sherrit, Zensheu Chang, Lauren Wessel, Xiaoqi Bao, Peter Doran, Chris Fritsen, Fabien Kenig, Christopher McKay, Alison Murray, Thomas Peterson

Proceedings Volume 5388, (2004) https://doi.org/10.1117/12.539280

KEYWORDS: Actuators, Mars, Prototyping, Planets, Astrobiology, Statistical analysis, Solids, Thermal modeling, Ultrasonics, Baryon acoustic oscillations

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Proceedings Article | 29 July 2004 Paper

Design and analysis of ultrasonic horn for USDC (ultrasonic/sonic driller/corer)

Zensheu Chang, Stewart Sherrit, Xiaoqi Bao, Yoseph Bar-Cohen

Proceedings Volume 5388, (2004) https://doi.org/10.1117/12.540000

KEYWORDS: Ultrasonics, Actuators, Finite element methods, Neck, Transducers, Interfaces, Performance modeling, Modal analysis, Baryon acoustic oscillations, Statistical analysis

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Proceedings Article | 27 July 2004 Paper

Characterization of bending EAP beam actuators

Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang, Stewart Sherrit

Proceedings Volume 5385, (2004) https://doi.org/10.1117/12.539083

KEYWORDS: Electroactive polymers, Actuators, Beam shaping, Image acquisition, Polymers, Software development, Software, Sensors, CCD cameras, Statistical analysis

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Proceedings Article | 21 July 2004 Paper

Resonance analysis of high-temperature piezoelectric materials for actuation and sensing

Stewart Sherrit, Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang

Proceedings Volume 5387, (2004) https://doi.org/10.1117/12.540102

KEYWORDS: Temperature metrology, Actuators, Venus, Bismuth, Sensors, Capacitance, Crystals, Crystallography, Solid state physics, Signal analyzers

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Proceedings Article | 5 August 2003 Paper

An ultrasonic sampler and sensor platform for in situ astrobiological exploration

Yoseph Bar-Cohen, Xiaoqi Bao, Zensheu Chang, Stewart Sherrit

Proceedings Volume 5056, (2003) https://doi.org/10.1117/12.483391

KEYWORDS: Ultrasonics, Sensors, Actuators, Mars, Baryon acoustic oscillations, Statistical analysis, Interfaces, Software development, Temperature metrology, Space operations

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Proceedings Article | 5 August 2003 Paper

In situ rock probing using the ultrasonic/sonic driller/corer (USDC)

Zensheu Chang, Stewart Sherrit, Xiaoqi Bao, Yoseph Bar-Cohen

Proceedings Volume 5056, (2003) https://doi.org/10.1117/12.483403

KEYWORDS: Actuators, Transducers, Ultrasonics, Statistical analysis, Sensors, Surface roughness, Signal generators, Aluminum, Nondestructive evaluation, Biological research

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Proceedings Article | 28 July 2003 Paper

Numerical modeling of single-layer electroactive polymer mirrors for space applications

Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang, Stewart Sherrit

Proceedings Volume 5051, (2003) https://doi.org/10.1117/12.484399

KEYWORDS: Mirrors, Electroactive polymers, Thin films, Finite element methods, Space mirrors, Electrodes, Polymers, Numerical modeling, Antennas, Space operations

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Proceedings Article | 22 July 2003 Paper

BAW and SAW sensors for in situ analysis

Stewart Sherrit, Xiaoqi Bao, Yoseph Bar-Cohen, Zensheu Chang

Proceedings Volume 5050, (2003) https://doi.org/10.1117/12.484252

KEYWORDS: Sensors, Resonators, Acoustics, Quartz, Crystals, Chemical analysis, Reflectors, Electrodes, Temperature metrology, Systems modeling

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Proceedings Article | 11 March 2003 Paper

Enabling novel space and terrestrial applications using transducing materials at JPL

Yoseph Bar-Cohen, Stewart Sherrit, Xiaoqi Bao, Zensheu Chang

Proceedings Volume 4946, (2003) https://doi.org/10.1117/12.468370

KEYWORDS: Electroactive polymers, Ultrasonics, Actuators, Robots, Robotics, 3D modeling, Haptic technology, Baryon acoustic oscillations, Interfaces, Artificial muscles

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Proceedings Article | 15 July 2002 Paper

Novel horn designs for ultrasonic/sonic cleaning, welding, soldering, cutting, and drilling

Stewart Sherrit, Steven Askins, Mike Gradziol, Benjamin Dolgin, Xiaoqi Bao, Zensheu Chang, Yoseph Bar-Cohen

Proceedings Volume 4701, (2002) https://doi.org/10.1117/12.474671

KEYWORDS: Ultrasonics, Acoustics, Titanium, Solids, Transducers, Manufacturing, Finite element methods, Signal attenuation, Resonators, SolidWorks

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A variety of Industrial applications exist where power ultrasonic elements such as the ultrasonic horn are used. These included the Automotive, Instruments, Foods, Medical, Textiles and Material Joining and Fabrication Industries. In many of these devices the ultrasonic horn is the key component. The standard transducer used in these devices consists of three main parts, the backing, the piezoelectric elements and the horn. Standard horn designs have changed very little since their inception. There are four common types of standard horns. They are; constant, linear, exponential and stepped, which refer to the degree to which the area changes from the base to the tip. A magnification in the strain occurs in the horn that in general is a function of the ratio of diameters. In addition the device is generally driven at resonance to further amplify the strain. The resonance amplification is in general determined by the mechanical Q (attenuation) of the horn material and radiation damping. The horn length primarily determines the resonance frequency. For a 22 kHz resonance frequency a stepped horn of titanium has a length of approximately 8 cm. Although these standard horns are found in many current industrial designs they suffer from some key limitations. In many applications it would be useful to reduce the resonance frequency however this would require device lengths of the order of fractions of meters which may be impractical. In addition, manufacturing a horn requires the turning down of the stock material (eg. Titanium) from the larger outer diameter to the horn tip diameter, which is both time consuming and wasteful. In this paper we will present a variety of novel horn designs, which overcome some of the limitations discussed above. One particular design that has been found to overcome these limitations is the folded horn. In this design the horn elements are folded which reduce the overall length of the resonator (physical length) but maintain or increase the acoustic length. In addition initial experiments indicate that the tip displacement can be further adjusted by phasing the bending displacements and the extensional displacements. The experimental results for a variety of these and other novel horn designs will be presented and compared to the results predicted by theory.

Proceedings Article | 15 July 2002 Paper

Analysis and simulation of the ultrasonic/sonic driller/corer (USDC)

Xiaoqi Bao, Zensheu Chang, Stewart Sherrit, Benjamin Dolgin, Yoseph Bar-Cohen, Dharmendra Pal, Shu Du, Thomas Peterson

Proceedings Volume 4701, (2002) https://doi.org/10.1117/12.474673

KEYWORDS: Transducers, Ultrasonics, Finite element methods, Computer simulations, Wave propagation, Chemical elements, Software, Fermium, Instrument modeling, Algorithm development

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Proceedings Article | 15 July 2002 Paper

Modeling of particle flow due to ultrasonic drilling

Zensheu Chang, Benjamin Dolgin, Xiaoqi Bao, Stewart Sherrit, Yoseph Bar-Cohen

Proceedings Volume 4701, (2002) https://doi.org/10.1117/12.474672

KEYWORDS: Particles, Contamination, Finite difference methods, Ultrasonics, Software, Mars, Algorithm development, Complex systems, Computer programming, Chlorine

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Proceedings Article | 11 July 2002 Paper

Use of piezoelectric resonators for the characterization of mechanical properties of polymers

Stewart Sherrit, Virginia Olazabal, Jose Sansinena, Xiaoqi Bao, Zensheu Chang, Yoseph Bar-Cohen

Proceedings Volume 4695, (2002) https://doi.org/10.1117/12.475175

KEYWORDS: Acoustics, Resonators, Quartz, Chemical elements, Composites, Polymers, Crystals, Capacitance, Aluminum, Transformers

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Proceedings Article | 16 August 2001 Paper

Ultrasonic/sonic drilling/coring (USDC) for planetary applications

Yoseph Bar-Cohen, Stewart Sherrit, Benjamin Dolgin, Xiaoqi Bao, Zensheu Chang, Dharmendra Pal, Ron Krahe, Jason Kroh, Shu Du, Thomas Peterson

Proceedings Volume 4327, (2001) https://doi.org/10.1117/12.436556

KEYWORDS: Acoustics, Mars, Ultrasonics, Data modeling, Finite element methods, Statistical analysis, Venus, Motion models, Ceramics, Temperature metrology

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Proceedings Article | 16 August 2001 Paper

Piezoelectrically actuated miniature peristaltic pump

Yoseph Bar-Cohen, Zensheu Chang

Proceedings Volume 4327, (2001) https://doi.org/10.1117/12.436554

KEYWORDS: Finite element methods, Metals, Actuators, Wave propagation, Interfaces, Liquids, Ultrasonics, Motion models, Aluminum, Aerospace engineering

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Proceedings Article | 14 June 2000 Paper

Piezoelectrically actuated miniature peristaltic pump

Yoseph Bar-Cohen, Zensheu Chang

Proceedings Volume 3992, (2000) https://doi.org/10.1117/12.388190

KEYWORDS: Finite element methods, Metals, Actuators, Interfaces, Liquids, Wave propagation, Ultrasonics, Motion models, Aluminum, Reliability

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Proceedings Article | 28 January 1999 Paper

Composite materials stiffness determination and defects characterization using enhanced leaky Lamb wave dispersion data acquisition method

Yoseph Bar-Cohen, Ajit Mal, Shyh-Shiuh Lih, Zensheu Chang

Proceedings Volume 3586, (1999) https://doi.org/10.1117/12.339892

KEYWORDS: Composites, Data acquisition, Nondestructive evaluation, Wave plates, Dispersion, Reflection, Data processing, Ultrasonics, Scanners, Inspection

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Proceedings Article | 31 March 1998 Paper

Composite material defect characterization using leaky Lamb wave dispersion data

Yoseph Bar-Cohen, Ajit Mal, Zensheu Chang

Proceedings Volume 3396, (1998) https://doi.org/10.1117/12.301519

KEYWORDS: Composites, Nondestructive evaluation, Data acquisition, Dispersion, Data modeling, Scanners, Heat treatments, Wave plates, Reflection, Ultrasonics

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Proceedings Article | 31 March 1998 Paper

NDE of rivet holes in aging aircraft components using Lamb waves

Ajit Mal, Zensheu Chang

Proceedings Volume 3397, (1998) https://doi.org/10.1117/12.305037

KEYWORDS: Waveguides, Transducers, Nondestructive evaluation, Wave plates, Wave propagation, Corrosion, Inspection, Finite element methods, Phase velocity, Defect detection

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Proceedings Article | 14 November 1996 Paper

Lap-joint inspection using plate waves

Ajit Mal, Zensheu Chang, Dawei Guo, Michael Gorman

Proceedings Volume 2945, (1996) https://doi.org/10.1117/12.259085

KEYWORDS: Wave plates, Waveguides, Inspection, Wave propagation, Finite element methods, Sensors, Phase velocity, Transducers, Receivers, Aluminum

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Showing 5 of 49 publications

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